Compare lactulose vs. Metamucil

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Generlac
(Lactulose)

Metamucil
(Psyllium)

Coming soon.Helps get things moving. The natural psyllium fiber in Metamucil (Psyllium) does more than relieve constipation. It lowers cholesterol, keeps blood sugar levels healthy, and makes you feel less hungry between meals.
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Reviews & ratings
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Reviews for Metamucil (Psyllium)
71%
29% vs. Generlac (Lactulose)
45%
55% vs. Generlac (Lactulose)
10%
10% vs. Generlac (Lactulose)
Side effects
lactuloseMetamucil

We haven’t found good data for lactulose side effects.

FDA side effect reports for lactulose »

We haven’t found good data for Metamucil side effects.

FDA side effect reports for Metamucil »
How it works
lactuloseMetamucil
Coming soon.Metamucil (Psyllium) is a fiber-based laxative. It adds bulk and moisture to your intestine, which softens stool and makes it easier to pass.
Type of medication
lactuloseMetamucil
Coming soon.
Laxative
Bulk-producing
Over-the-counter
Available as
lactuloseMetamucil
  • Liquid
  • Liquid
Used for (click to learn more)
lactuloseMetamucil
  • Constipation Hepatic encephalopathy; Treatment and Prophylaxis
Risk factors for serious side effects
lactuloseMetamucil
Coming soon.
  • Age 60 or older
  • Malignancy
  • Other condition that causes blockage or narrowing of bowel
  • Taking medications that cause constipation
  • Sensitivity to psyllium
Detailed Metamucil (Psyllium) risks & warnings »
Pregnancy category
lactuloseMetamucil
BFDA pregnancy category (Probably safe)

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

See the FDA package insert
NFDA pregnancy category (Unknown)

The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

See the FDA package insert
Alcohol
No specific alcohol-related info.No specific alcohol-related info.
Food
No specific food-related info.
  • It has multiple health benefits, good to control your hunger between meals, improves your blood sugar and lowers cholesterol levels.
  • Talk to you doctor about eating certain foods and getting more exercise to help prevent your constipation.
Kidneys and liver
No specific kidneys and liver-related info.No specific kidneys and liver-related info.
Sex
No specific sex-related info.No specific sex-related info.
Sleep
No specific sleep-related info.No specific sleep-related info.
Weight
No specific weight-related info.No specific weight-related info.
Upsides and benefits
lactuloseMetamucil
Coming soon.
  • Psyllium is the most recommended brand of natural fiber laxative
  • Some people feel that taking Psyllium is a hassle, but most think it's worth it.
  • It has multiple health benefits, good to control your hunger between meals, improves your blood sugar and lowers cholesterol levels.
  • Studies show it works better than a stool softener for constipation.
Downsides and risks
lactuloseMetamucil
Coming soon.
  • You may have to take Psyllium daily for 1-3 days to see full effects.
  • If you don't take it with enough liquid, it could swell, block your throat and cause choking.
  • Not the best choice for people who have swallowing problems or aren't able to drink lots of liquids.
  • Psyllium contains psyllium. Don't take if you have an allergy to psyllium from breathing it in or swallowing it.
  • Can cause gas and mild belly cramps.
Tips from our pharmacists for people taking the medication
lactuloseMetamucil
Coming soon.
  • Psyllium works in about 12-72 hours for constipation.
  • It's important to take each dose with at least 8 ounces (a full glass) of water or other liquid (not hot liquids).
  • Mix powder well and drink right away up to 3 times a day (build up to this slowly), but not for more than one week.
  • Don't take Psyllium within 2 hours before or after taking other medicines. It may interact and affect how they work.
  • If you take Psyllium then have chest pain, vomiting, trouble breathing or swallowing, get medical help immediately.
  • Ask your doctor before taking Psyllium if you have stomach pain, nausea, vomiting or had sudden changes in your stool for more than 2 weeks.
  • Ask your doctor about giving Psyllium to anyone younger than 12 years.
  • Stop taking Psyllium and call your doctor if you have pain, swelling or bulging in your belly, rectal bleeding or have not had a bowel movement after taking.
  • Talk to you doctor about eating certain foods and getting more exercise to help prevent your constipation.
Learn more
More about lactuloseSide effectsReviews & ratingsFDA package insert
More about MetamucilSide effectsReviews & ratingsAlternativesFDA package insert